diff --git a/src/main/java/de/neemann/digital/analyse/parser/Tokenizer.java b/src/main/java/de/neemann/digital/analyse/parser/Tokenizer.java
index 132f6d9a2..c07eff250 100644
--- a/src/main/java/de/neemann/digital/analyse/parser/Tokenizer.java
+++ b/src/main/java/de/neemann/digital/analyse/parser/Tokenizer.java
@@ -4,6 +4,8 @@ import java.io.IOException;
 import java.io.Reader;
 
 /**
+ * Simple tokenizer to tokenize boolean expressions.
+ *
  * @author hneemann
  */
 public class Tokenizer {
diff --git a/src/main/java/de/neemann/digital/analyse/parser/package-info.java b/src/main/java/de/neemann/digital/analyse/parser/package-info.java
index 2f5533226..daae27ec2 100644
--- a/src/main/java/de/neemann/digital/analyse/parser/package-info.java
+++ b/src/main/java/de/neemann/digital/analyse/parser/package-info.java
@@ -1,5 +1,6 @@
 /**
- * Classes to parse an expression to an {@link de.neemann.digital.analyse.expression.Expression} instance.
+ * Classes to parse an expression given as a string or reader to an
+ * {@link de.neemann.digital.analyse.expression.Expression} instance.
  *
  * @author hneemann
  */